By posting on its own website a threat to attack Kenya, and then disavowing that threat as a “fake,” Somali insurgent group Al Shabab may seem a bit confused.

But that doesn’t make either the threat or the people who made the threat any less dangerous, nor Kenya any less vulnerable, security analysts say. It may indicate a split among the group's leadership between jihadists and nationalists.

With hundreds of thousands of Somali refugees residing within its borders, and a sizable indigenous Somali ethnic community as well, Kenya must remain vigilant against potential threats such as the Islamist Al-Shabab militia, which professes close ties to and a shared ideology with Al Qaeda. Kenya’s vulnerability was seen plainly last week, after protests over the planned deportation of a radical Jamaican cleric turned violent in Nairobi’s Somali neighborhood of Eastleigh, and as protesters unfurled the black flag of Al Shabab to show their radical allegiances.

“If the Mungiki [an ethnic Kikuyu militia] can carry out attacks in Nairobi, anybody can,” says Richard Cornwell, a veteran Africa analyst from Tshwane (Pretoria). “Whether this is really Al Shabab or ordinary criminal elements pretending to act in the defense of Islam – we’re more than just bandits, we’re religious bandits – it doesn’t really matter. They can do bloody well what they want.”